Clamp sensor for temperature measurements on pipes with a diameter of 6 to 35 mm, NTC. Use the clamp sensor (NTC) to accurately measure surface temperatures on pipes of heating systems, water lines, refrigeration systems, or heat pumps. Depending on the connected measuring device, the clamp sensor can be used to identify overheating or undercooling in refrigeration systems or to determine supply and return temperatures in heating technology. The clamping mechanism allows for quick and easy attachment of the surface sensor.